Methods, arrangements and structures relating to the technical field mentioned above and having a function and a structure which fulfill the requirements set up are known earlier in a plurality of different embodiments.
As a first example of the background of technology and the technical field to which the invention refers may be mentioned a chuck-related arrangement, having three chuck jaws, as shown and described in the following with reference to the accompanying FIG. 1.
The structure of this arrangement will be described more specifically in connection with the following, below the text portion “Description of known technology”.
Arrangements of a relevant type are based on that the main portion allotted to the chuck is to be coordinated with radially oriented two, (or four) chuck jaws, wherein each one is mutually coordinated with and radially displaceable along, in the main portion shaped, radially oriented tracks and/or individually displaceable along said tracks, alternatively being solidly related to the main portion, as a solid counter-engagement portion.
This displacement movement of the chuck jaws is normally synchronized or coordinated for common motion towards and away from a (horizontal) center axis, allotted to the main portion for holding an unprocessed, such as a cylinder-shaped, work piece or removing and letting go of a work piece after such a processing.
To the earlier standpoint of technology there also belongs a chuck-related arrangement having solely two diametrically oriented chuck jaws (according to FIG. 2) or four (two and two) diametrically oriented chuck jaws, wherein a first-mentioned embodiment, in accordance with FIG. 2, also will be described in the following under the text portion “Description of known technology”.
To the earlier standpoint of technology also belongs different means coordinated with the main portion and their allotted means, in the form of T-track nuts, for a radial displacement of each jaw part, and as the existence of these means do not comprise an essential portion of the present invention, these means will solely be noted in the following.
The contents of International Patent Publication WO 95/26248-A1 also belong to the earlier standpoint of technology, wherein is shown and described a chuck-related arrangement (21) adapted for use in a lathe chuck (23), with the arrangement being such that the three chuck jaw portions with associated clamping surfaces, in a free from the chuck and in a dismounted position, being turnably positioned into each of four positions around a common fictionary shaft (41) and cooperating with each of three radial tracks in the chuck.
This arrangement (21) comprises at least three cylindrical units (36), wherein each unit is allotted a lengthwise oriented shaft (41) having an external cylindrical surface (42) and having the surfaces (43, 46) disposed at right angles to the shaft (41).
Each unit (36) is allotted three evenly distributed recesses (51, 52, 53, 54) in the cylindrical surfaces (42) and (43).
Each unit (36) cooperates with a track (27), having a T-track nut, for being able to safely anchor the chuck-related arrangement (21).
This patent publication proposes a chuck-related arrangement which, similar to ordinarily existing chuck jaw parts, requires a long time and is elaborate when a complete jaw-associated unit (36) is to be changed with regard to its setting or shifted to an entirely different unit allotted to chuck jaw parts.
These allotted units (36) can only be mounted one by one as one single unit in the four (4) different positions, which are offered by the set-up track (27) of the chuck.
Each entirely new unit or changed unit requires having two screws (bolt arrangements) loosened and removed entirely, whereafter the complete or whole unit (36) can be displaced as a free and single unit and can be shifted manually to a new position, so as to be tightened again in this new position by means of the earlier loosened two screws.
It should also be noted that for each shifting of unit (36) it is required that said unit (36) is cleaned or cleansed as well as its track (27), with its T-track nut, in the chuck (23) so as thereby to be able to ensure the required security.
Basically this patent publication refers to a chuck-related arrangement (21) which is completely in agreement with known technology but with the difference that here suggests the utilization of cylindrical chuck jaw parts with associated clamping surfaces which, not until being completely loosened and removed, become entirely turnable around their fictive axes (41) of rotation so as in the rotation (turning) enabling the use of four separated available clamping surfaces but where the units (36) are, in the same manner as ordinary chuck jaw parts, attached to the track (27) and its T-track nut with the assistance of two bolts, wherein a first bolt (67) is to be extended through a centrally located hole (62) and a second bolt is to be extended through one of two available external holes (63), exposing a function which differs entirely from the present invention.
It is noted that in known technology the jaws or jaw parts or portions will, in a mounting indicated by the patent publication, always utilize two fastening screws against the T-track nut for a displacement along radial tracks in the chuck.
The embodiment shown and illustrated here of the arrangement with the four partially shown cylindrical clamping surfaces will, in consequence of its purely cylindrically shaped external surface, not be able to enable the attachment or clamping of very small work pieces with their associated small diameters without first a change being carried out of the realization and shape of the jaws for being directly adapted to these small diameters, as cylindrically shaped external surfaces will cause a limitation.